Flush toilet

ABSTRACT

Provided is a flush toilet capable of suppressing a decrease in water force of flush water and effectively exhibiting the excrement discharge performance. The flush toilet includes: a toilet bowl having a bowl surface part and a recessed part formed below the bowl surface part and continued to a drain pipe; and a water discharge port for discharging flush water into the toilet bowl. The flush water forms at least two water streams and flows into the recessed part. A first water stream flows from the front part of the toilet bowl into the recessed part and a second water stream flows from the rear part of the toilet bowl into the recessed part

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage patent application under 35 U.S.C. 371 of International Application No. PCT/JP2017/039971, filed Nov. 6, 2017, which claims priority to Japanese Application No. 2016-252708, filed Dec. 27, 2016, each of which are hereby incorporated by reference in the present disclosure in its entirety.

FIELD OF THE INVENTION

The present disclosure relates to a flush toilet.

BACKGROUND OF THE INVENTION

Patent Literature 1 discloses a flush toilet including: a toilet bowl (bowl part) having a bowl surface part (excrement receiving surface) and a recessed part formed below the bowl surface part and continued to a drain pipe; and a water discharge port (rim water discharge port) for discharging flush water into the toilet bowl. In addition, this flush toilet includes a water discharge port (jet water discharge port) for discharging flush water directly into the recessed part. The flush water discharged from the rim water discharge port washes the bowl surface part and flows along the surface of the bowl surface part into the recessed part. In addition, the flush water discharged from the jet water discharge port forms a swirling flow that swirls upward from the bottom wall along the surface of the recessed part.

-   Patent Literature 1: JP 2013-194410 A

SUMMARY OF THE INVENTION

In the case of the flush toilet as described above, there are generated a descending water stream of flush water flowing from above into the recessed part along the surface of the bowl surface part and an ascending water stream of flush water which swirls in the vertical direction within the recessed part. Therefore, these water streams may collide against each other within the recessed part. In this case, there arises a problem that the water forces of the respective water streams are weakened so that excrement cannot be sufficiently discharged.

Embodiments of the present invention have been made in view of the above-described conventional circumstances, and an object thereof is to provide a flush toilet capable of suppressing a decrease in water force of flush water and effectively exhibiting the excrement discharging performance.

In some embodiments, a flush toilet includes:

a toilet bowl having a bowl surface part and a recessed part formed below the bowl surface part and continued to a drain pipe; and

a water discharge port for discharging flush water into the toilet bowl,

wherein the flush water forms at least two water streams and flows into the recessed part, the two water streams being a first water stream flowing from a front part of the toilet bowl into the recessed part and a second water stream flowing from a rear part of the toilet bowl into the recessed part and ascending on a front side of the recessed part thereby swirling in a vertical direction within the recessed part, and

wherein a step part which is stepped in the vertical direction is formed in a region of the bowl surface part where the first water stream runs down.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a plan view showing a flush according to some embodiments;

FIG. 2 is a perspective view showing the flush toilet according to some embodiments;

FIG. 3 is a cross-sectional view taken along line of FIG. 1 according to some embodiments;

FIG. 4 is a cross-sectional view taken along line Iv-Iv of FIG. 1 according to some embodiments;

FIG. 5 is a diagram for explaining the action of the flush toilet according to some embodiments;

FIG. 6 is a diagram for explaining the action of the flush toilet according to some embodiments;

FIG. 7 is a diagram for explaining the action of the flush toilet according to some embodiments; and

FIG. 8 is an enlarged view of a main part of FIG. 7 according to some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

In some embodiments, the first water stream flows from the front part of the toilet bowl into the recessed part, and the second water stream flows from the rear part of the toilet bowl into the recessed part and ascends on the front side of the recessed part, thereby swirling in the vertical direction within the recessed part. Further, the first water stream can pass through the step part and thereby forms a flow away from the surface of the bowl surface part. Due to this, when the two water streams join within the recessed part, head-on collision of these water streams in the respective traveling directions may be avoided, thereby making it possible to suppress a decrease in water force.

Therefore, flush toilets described herein can suppress a decrease in water force of flush water and effectively exhibit the excrement discharge performance.

In some embodiments, a step part may be formed extending in a horizontal direction along a surface of the bowl surface part. In this case, even though the first water stream may flow down spreading in the horizontal direction along the surface of the bowl surface part or may change flow-down position due to variations in water force and the like, the first water stream can be reliably caused to flow to the step part.

The above “horizontal direction” does not have to be strictly horizontal, and also encompasses an obliquely vertical direction.

In the following description, as for a front-back direction, the lower side in FIG. 1 and the left side in FIG. 3 are each defined as a front side. As for a lateral direction, the left and right sides in FIG. 1 are defined as left and right sides as they are. A flush toilet 1 of the present embodiment includes a toilet bowl 10 and water discharge ports 21, 22.

As shown in FIGS. 1 to 3, the toilet bowl 10 has an erected surface part 11, a bowl surface part 12, a shelf surface part 13, and a recessed part 14. The erected surface part 11 is provided at the upper end part of the toilet bowl 10, and the surface thereof is formed extending in the vertical direction. The erected surface part 11 is formed over substantially the entire circumference of the upper end part of the toilet bowl 10. The erected surface part 11 is formed in an annular shape slightly longer in the front-back direction in a plan view and has an egg shape in which the curvature of the front part is larger than that of the rear part. The upper end surface of the erected surface part 11 extends outward and substantially horizontally at a substantially constant height. Thus, the flush toilet 1 is a toilet having no overhanging part projecting inward from the upper end of the erected surface part 11.

In some embodiments, the bowl surface part 12 is formed in a mortar shape below the lower end of the erected surface part 11 to the inner circumferential side. The bowl surface part 12 is formed inclined so as to be lower toward the center rear side. The shelf surface part 13 is provided between the erected surface part 11 and the bowl surface part 12 so as to connect the lower end of the erected surface part 11 and the upper end of the bowl surface part 12. The shelf surface part 13 has a surface facing upward, and extends slightly inclining downward as it goes inward. The shelf surface part 13 is provided in a peripheral edge of the toilet bowl 10 except a part of the front side, and is formed in a substantially horseshoe shape in a plan view. The recessed part 14 is formed below the bowl surface part 12 and continued to a drain pipe 30. The recessed part 14 is provided continuously with the lower end of the bowl surface part 12. The recessed part 14 is disposed at substantially the center in the lateral direction and near the rear side of the toilet bowl 10. In the recessed part 14, reserved water composed of flush water is formed.

In some embodiments, the water discharge ports 21, 22 are opened in the erected surface part 11 of the toilet bowl 10 and discharge the flush water into the toilet bowl 10. In some embodiments, two water discharge ports, i.e., the first water discharge port 21 and the second water discharge port 22 are provided as the water discharge ports. The two water discharge ports 21, 22 each discharge the flush water into the toilet bowl 10. The discharged flush water flows on the shelf surface part 13 and the bowl surface part 12 within the toilet bowl 10 while swirling counterclockwise, flows into the recessed part 14, and is discharged to the drain pipe 30.

Specifically, the first water discharge port 21 is provided opened on the left rear side of the toilet bowl 10. The flush water discharged from the first water discharge port 21 is discharged onto the shelf surface part 13 toward the front side, and a part thereof becomes a part of a main stream F1, as will be described later, which flows in the peripheral edge of the toilet bowl 10 along the erected surface part 11. Another part of the flush water becomes a part of a branch stream F2, as will be described later, which runs down from the shelf surface part 13 to the bowl surface part 12 side. Still another part of the flush water becomes a part of a second water stream F4, as will be described later, which flows into the recessed part 14.

The second water discharge port 22 is provided opened on the right rear side of the toilet bowl 10. The flush water discharged from the second water discharge port 22 is discharged toward the left side slightly to the front side, and a part thereof joins the flush water discharged from the first water discharge port 21. The other part becomes a part of the second water stream F4 which runs down to the bowl surface part 12 side and flows into the recessed part 14. In some embodiments, the amount of flush water to be used in one flush is set to about 5 liters. The flush water in the amount for one flush is stored in a tank (not shown) in advance. The discharge flow rate (amount of water to be discharged per unit time) of the flush water is almost maximum at the beginning of discharge, and then gradually decreases.

In some embodiments, as shown in FIGS. 1 and 2, the flush water flows so as to form mainly four water streams F1 to F4 in the toilet bowl 10. Among these water streams, the main stream F1 and the branch stream F2 are water streams that are discharged from the water discharge ports 21, 22 and swirl within the toilet bowl 10. The first water stream F3 and the second water stream F4 are water streams that run down into the recessed part 14.

The flush water discharged from the water discharge ports 21, 22 forms at least two water streams, i.e., the main stream F1 and the branch stream F2, and washes the inside of the toilet bowl 10. That is, a part of the flush water flows so as to form the main stream F1 and the branch stream F2. Among these water streams, the main stream F1 is a water stream that flows in the peripheral edge of the toilet bowl 10 along the erected surface part 11. The branch stream F2 is a water stream that branches from the main stream F1 and runs down to the bowl surface part 12 side. The branch stream F2 joins the main stream F1 at a joining part Jon the downstream side. In the flush water forming these two water streams F1, F2, the main stream F1 arrives at the joining part J earlier than the branch stream F2. In detail, the branch stream F2 branches from the main stream F1, flows down to the bowl surface part 12 side thereby washing the surface of the bowl surface part 12, and flows into the recessed part 14, whereas a part of the branch stream F2 joins the main stream F1 at the joining part J on the downstream side. Among the main stream F1 and branch stream F2 joining at the joining part J, the main stream F1 that first arrives at the joining part J immediately after the beginning of discharge of the flush water into the toilet bowl 10 arrives earlier than the branch stream F2 that first arrives at the joining part J immediately after the beginning of discharge.

In some embodiments, such joining configuration of the main stream F1 and the branch stream F2 is realized by adjusting the flow distance of the branch stream F2 by recessing deeply downward the surface of the bowl surface part 12 which serves as a flow path to the joining part J of the branch stream F2. That is, as shown in FIGS. 3 to 5, the surface height of a portion of the bowl surface part 12 where the branch stream F2 flows is made sufficiently deeper than the flow height of the main stream F1 (height of the shelf surface part 13), whereby the moving distance of the branch stream F2 is set to be longer. That is, the length of the moving distance of the branch stream F2 is set by utilizing the height difference in a period from when the branch stream F2 branches from the main stream F1 at the height of the shelf surface part 13 to when it joins again the main stream F1 in the joining part J at the height of the shelf surface part 13. In some embodiments, the moving distance of the branch stream F2 in a period from when it branches from the main stream F1 to when it arrives at the joining part J is set to be longer than the moving distance of the main stream F1 in a period from when the branch stream F2 branches therefrom to when the main stream F1 arrives at the joining part J. Further, due to the height difference thus provided between the surface of the bowl surface part 12 and the surface of the shelf surface part 13, the water force of the branch stream F2 is weakened, whereby flow rate is reduced. This also affects the arrival timing of the branch stream F2 at the joining part J.

The joining part J is located on the downstream side of a region A which is located on the front side of the toilet bowl 10 and where the height of the main stream F1 is maximum. As shown in FIG. 6, the main stream F1 flowing along the erected surface part 11 in the peripheral edge of the toilet bowl 10 is pressed against the erected surface part 11 in the outer circumferential direction under the influence of the centrifugal force. The main stream F1 flows while changing its height according to the change in curvature of the erected surface part 11 and the flow rate. In FIG. 6, an imaginary line denoted by symbol M indicates a trajectory of the maximum arrival height of the flow which shows the position where the flow in the peripheral edge of the toilet bowl 10 flows the highest on the surface of the erected surface part 11 during the flushing. In the trajectory, the portion where the height of the main stream F1 is maximum on the front side of the toilet bowl 10 is the region A. If the branch stream F2 joins in this region A, the flush water may reach a much higher position and may scatter outside the toilet bowl 10. Therefore, in some embodiments, the position of the joining part J is set on the downstream side of the region A. In some embodiments, since the region A where the height of the main stream F1 is maximum is located at a rightward position on the front side of the toilet bowl 10, the joining part J is set to be located on a further downstream side of the position, as shown in FIG. 6.

In some embodiments, the portion where the height of the flow in the peripheral edge of the toilet bowl 10 is maximum on the front side of the toilet bowl 10 is the region A where the height of the main stream F1 is maximum. However, the flow may be maximum at the joining part J due to joining of the branch stream F2.

The above configuration is realized as follows. In some embodiments, the bowl surface part 12 is inclined in such a manner that the branch stream F2 immediately after the beginning of discharge from the water discharge port 21 is dropped into the recessed part 14 on an imaginary line V connecting the water discharge port 21 and the region A where the height of the main stream F1 is maximum in a plan view, as shown in FIG. 6. Specifically, as shown in FIG. 4, the inclination angles θ1, θ2 of the surface of the bowl surface part 12 are set to 45° or more (more preferably 60° or more). Further, in some embodiments, the inclination angle θ1 of the surface on the left side (upstream side) of the bowl surface part 12 is larger than the inclination angle θ2 of the surface on the right side (downstream side) thereof. Due to this, the branch stream F2 that tends to flow on the imaginary line V is drawn into the recessed part 14 side, so that the flush water is prevented from arriving at the region A linearly from the first water discharge port 21. Further, the flush water on the imaginary line V is drawn to the recessed part 14 side, whereby a force for energizing a swirl in a counterclockwise direction is applied to the branch stream F2, so that the branch stream F2 is caused to join on a further downstream side. In some embodiments, it is realized that the joining part J is located on the downstream side of the region A where the height of the main stream F1 is maximum. Further, the branch stream F2 that tends to flow on the imaginary line V is dropped into the recessed part 14 side, whereby the water amount of the branch stream F2 arriving at the joining part J is reduced and accordingly the water force and flow rate are reduced. As a result, the impact when the branch stream F2 joins the main stream F1 is moderated, thereby reliably preventing scattering of the flush water to the outside of the toilet bowl 10.

Further, in the branch stream F2, a component that tends to arrive at the region A linearly from the first water discharge port 21, that is, a component that tends to enter the surface of the erected surface part 11 with a large entry angle and tends to collide against the surface, runs down to the recessed part 14 side or the water force thereof is weakened, with the result that formation of a swirling flow is prompted. Due to this, when joining the main stream F1, the branch stream F2 which has become a swirling flow has a smaller entry angle with respect to the surface of the erected surface part 11, so that the branch stream F2 can smoothly join the main stream F1 flowing along the erected surface part 11. Therefore, the impact when the branch stream F2 joins the main stream F1 is further moderated, thereby more reliably preventing scattering of the flush water to the outside of the toilet bowl 10.

Further, as shown in FIGS. 1 and 2, the flush water forms at least two water streams, i.e., the first water stream F3 and the second water stream F4, and runs down into the recessed part 14. The first water stream F3 flows from the front part of the toilet bowl 10 into the recessed part 14. The second water stream F4 flows from the rear part of the toilet bowl 10 into the recessed part 14 and swirls in the vertical direction within the recessed part 14. Specifically, as shown in FIG. 7, the second water stream F4 having flowed into the recessed part 14 from the rear side of the toilet bowl 10 becomes an ascending stream on the front side of the recessed part 14 and swirls upward, and then becomes a descending stream again on the rear side of the recessed part 14, thus swirling in the vertical direction, and enters the drain pipe 30.

In a region of the bowl surface part 12 where the first water stream F3 runs down, a step part 12A which is stepped in the vertical direction is formed. As shown in FIGS. 7 and 8, the step part 12A is formed in the lower part of the bowl surface part 12, and the recessed part 14 is continued below the step part 12A. The step part 12A changes the flow direction of the first water stream F3. Specifically, the step part 12A acts so as to separate the first water stream F3, which tends to flow along the surface of the bowl surface part 12, from the surface of the bowl surface part 12 on the downstream side thereof. In some embodiments, the step part 12A is formed by recessing the surface of the bowl surface part 12 in a concave shape. The step part 12A is formed extending in the horizontal direction along the surface of the bowl surface part 12. That is, in some embodiments, the step part 12A has a predetermined width in the horizontal direction. According to this configuration, it is possible to cope with the first water stream F3 which may flow down spreading in the horizontal direction along the surface of the bowl surface part 12 or may change flow-down position due to variations in water force and the like.

As shown in FIG. 8, in the flow of the second water stream F4 swirling within the recessed part 14 in the vertical direction, the flow swirling upward is formed below the step part 12A. On the other hand, the first water stream F3 runs down from above the step part 12A. The first water stream F3 running downward passes through the step part 12A and thereby the flow direction thereof is changed, so that collision thereof against the second water stream F4 is avoided. The second water stream F4 having ascended from below the step part 12A descends inside the recessed part 14 and enters the drain pipe 30. In addition, the first water stream F3 passes through the step part 12A and thereby the flow direction thereof is changed to substantially the same direction as the flow direction of the second water stream F4, and thus the first water stream F3 joins the second water stream F4. Accordingly, the second water stream F4 can enter the drain pipe 30 while the water force is maintained. Therefore, the capability of pushing excrement from the recessed part 14 into the drain pipe 30 is improved as compared with the case where the water force is weakened by the collision between the first water stream F3 and the second water stream F4.

As described above, the step part 12A has an action of separating the first water stream F3 passing therethrough from the surface of the bowl surface part 12, but it is not necessary to separate the whole amount thereof. A part of the first water stream F3 passing through the step part 12A may flow along the surface of the bowl surface part 12.

Further, the first water stream F3 having passed through the step part 12A joins the second water stream F4 within the recessed part 14 and enters the drain pipe 30. As described above, the first water stream F3 passes through the step part 12A so that the flow direction thereof is changed. As a result, the water force of the first water stream F3 is weakened and the flow rate is reduced. However, the cross-sectional area thereof is increased instead, with the result that the first water stream F3 having an increased thickness flows into the recessed part 14. Therefore, the capability of pushing excrement into the drain pipe 30 from the recessed part 14 is further improved.

As described above, the first water stream F3 flows from the front part of the toilet bowl 10 into the recessed part 14, and the second water stream F4 flows from the rear part of the toilet bowl 10 into the recessed part 14 and ascends on the front side of the recessed part 14, thereby swirling in the vertical direction within the recessed part 14. Further, the first water stream F3 passes through the step part 12A and thereby forms a flow away from the surface of the bowl surface part 12. Due to this, collision between the two water streams F3, F4 is avoided when joining within the recessed part 14, thereby making it possible to suppress a decrease in water force.

Therefore, the flush toilet 1 can suppress a decrease in water force of the flush water and effectively exhibit the excrement discharge performance.

Furthermore, in the flush toilet 1, the step part 12A is formed extending in the horizontal direction along the surface of the bowl surface part 12. Therefore, even though the first water stream F3 may flow down spreading in the horizontal direction along the surface of the bowl surface part 12 or may change flow-down position due to variations in water force and the like, the first water stream F3 can be reliably caused to flow to the step part 12A.

The present invention is not limited to the embodiments described above and with reference to the drawings, and, for example, the embodiments described below also fall within the technical scope of the present invention.

(1) In some embodiments, the main stream arrives first at the joining part where the main stream and the branch stream join, but this is not essential.

(2) In some embodiments, a toilet bowl has a horseshoe-shaped shelf surface part in a plan view, but this is not essential. Further, when the toilet bowl has a shelf surface part, not only the above-described configuration but also other configurations may be adopted, for example, the shelf surface part may be formed over the entire circumference of the toilet bowl, or the shelf surface part may be formed in a narrower range such as a substantially semicircular shape in a plan view.

(3) In some embodiments, an overhanging part projecting inward from the upper end of the erected surface part is not provided. However, an overhanging part may be formed in a part of the upper end of the toilet bowl or over the entire circumference of the toilet bowl.

(4) In some embodiments, two water discharge ports are provided, but one water discharge port or three or more water discharge ports may be provided. Further, in the case where a plurality of water discharge ports is provided, the second and subsequent water discharge ports are not necessarily water discharge ports for generating a swirling flow. For example, the water discharge ports may be intended to discharge water only downward.

(5) In some embodiments, the water discharge ports are disposed on the rear side of the toilet bowl, but the positions of the water discharge ports are not particularly limited. In addition, the discharging direction of the flush water from the water discharge ports and the swirling direction within the toilet bowl according to the discharging direction are also not limited.

(6) In some embodiments, the step part extends in the horizontal direction along the surface of the bowl surface part, but in this case, the length of the step part is not particularly limited. Further, the extending direction of the step part may be not only the horizontal direction, but also a direction other than the horizontal direction, including the vertical direction.

(7) In some embodiments, the bowl surface part is inclined in such a manner that the branch stream after the beginning of discharge from the water discharge port is dropped into the recessed part on the imaginary line connecting the water discharge port and the region where the height of the main stream F1 is maximum, in order for the joining part to be located on the downstream side of the region where the height of the main stream is maximum. However, it is not essential that the joining part is located on the downstream side of the region where the height of the main stream is maximum.

(8) In some embodiments, the step part is formed by recessing the surface of the bowl surface part in a concave shape, but the step part may be formed by bulging the surface of the bowl surface part in a convex shape.

(9) In some embodiments, the moving distance of the branch stream in a period from when the branch stream branches from the main stream to when it arrives at the joining part is set to be longer than the moving distance of the main stream in a period from when the branch stream branches therefrom to when the main stream arrives at the joining part. However, this is not essential.

(10) In some embodiments, the recessed part is continued below the step part, but embodiments of the present invention are not limited thereto. The step part may be formed at a position separated from the recessed part above the lower end of the bowl surface part as long as the first water stream flows away from the surface of the bowl surface part into the recessed part. 

1. A flush toilet comprising: a toilet bowl comprising a bowl surface part and a recessed part formed below the bowl surface part and continued to a drain pipe; and a water discharge port for discharging flush water into the toilet bowl, wherein the flush water forms at least two water streams and flows into the recessed part, the at least two water streams comprising a first water stream flowing from a front part of the toilet bowl into the recessed part and a second water stream flowing from a rear part of the toilet bowl into the recessed part and ascending on a front side of the recessed part thereby swirling in a vertical direction within the recessed part, and wherein a step part which is stepped in the vertical direction is formed in a region of the bowl surface part where the first water stream runs down.
 2. The flush toilet of claim 1, wherein the step part is formed extending in a horizontal direction along a surface of the bowl surface part. 